The later 700s had the same drivetrain as the later 240s.

The 700 is mechanically much the same, but a little bit more refined and spacious on the interior. The 240 is a little bit more rough around the edges, but is a great car as you already know. Volvo's last RWD cars, like from 91-95, including 240, 740, and 940, were the top of the heap. (Not that the older cars were not; but the later cars were a little more refined and had more options available). Any of them are a good choice, but common wisdom says avoid 16v engines. Again, the 16v engines are fine, but there is more to go wrong, that's all.

Refinement and option levels were the basic differences, aside from the cosmetics. Each has their strong and weak points.
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chris herbst, near chicago